Interrupter for ignition apparatus



Nov; 14, 1933. F. ALLENDORF F ET AL INTERRUPTERFOR IGNITION APPARATUS Filed March 3. 1932 Patented Nov. 14, 1933 UNITED STATES PATENT OFFICE INTERRUPTER FOR IGNITION APPARATUS v Application March 3, 1932, Serial No. 596,614,

and in Germany June 1, 1931 2 Claims.

The present invention relates to interrupters .ior ignition apparatus.

It is known that the wear of contacts of inter- I rupters is particularly heavy if they are exposed to the vapours of oil or to the oil itself. In order to protect the contacts from vapours, it has been already proposed to arrange the contacts in a separate compartment quite shut off from.

the cam. The transmission of the movement of the cam to the contacts takes place in such case through a partition Wall by means of a rocking lever revolubly mounted in the partition wall, or

even by means of a ram passing through the parbrane' as the partition wall, on which the rockingcontact is arranged or with which the-lever carrying the rocking contact is rigidly connected; but these arrangements have the drawback that the rocking contact is not'reliably guided.

According to the invention, these drawbacks are removed by the compartment for the contacts being closed by a flexiblenon-resiliently acting partition wallthrough which the device, such as the rocking lever or ram which carries the movable contact, is carried in a gas-tight manner. The invention is illustrated in an example of construction in the accompanying drawing in which: a

Figure 1 shows an interrupter, partly in section.

Figure 2 is a section on the line -AA of Fig. 1. Figure 3 a section on the line 3-3 of Fig. 1. In the drawing an interrupter of known construction is illustrated. On the base-plate a is secured with a screw b the supporting block c for the fixed contact d, and a bearing pin e for the rocking lever j, which carries the movable contact g. The base-plate is fastened, as it is a question in the example described of a rotating interrupter, by a screw'h and a conical pin on a driving shaft i. The'bearing block c is quite enclosed by "a casing is. The bottom ofthis casing is secured on' the base-plate between the bearing block c and an insulating disc m. Furthermore, the-casing is also secured by the contact pin n and the nut 0 on the bearing block 0. The cover 11 of the casing is retained in its position by a prolongation q of the screw IL and pressed by a nut r on the casing lc. On the side facing the movable contact g the casing is closed by a flexiblewall s of oiled canvas or like gas-tight material. The oiled canvas is secured on the edge of the casing by a metal band if pushed over it, and is stretched between the rocking lever f and a disc u, which is pressed by the collar 11 on the contact pin w against the rocking lever f. The oiled canvas is so loosely stretched that it can easily follow the movements of the rocking lever.

In order to ventilate the contact compartment formed by the casing, a passage y is bored in the extension q of the screwbolt h projecting through an opening x in the cover of the interrupter, which passage reaches to the head of the screw h and there connects with a passage 2 perpendicular to it in the head of the screw.

The flexible wall s not only keeps away from the contacts injurious oil vapours coming from the cam and the bearing pin e, or even from ignition apparatus on which the interrupter is fitted, but it has by its movement to and fro a bellows-like action. In order that fresh air may penetrate into the casing, the volume or capacity of the passages y and 2 together must be smaller than the volume displaced by the wall in its movement.

The constructiondescribed represents only a particular case. Contacts'of stationary interrupters having a rotating cam, or those interrupters in which the movable contact is mounted on a ram operated by the cam can be closed and ventilated in a similar way.

By the invention it is possible to considerably prolong the life of known and approved interrupters in which the movable contact is guided with certainty by a rocking lever or a ram, and a it is also possible to install the arrangement according to the invention subsequently on existing interrupters without special cost.. A further advantage is aiforded by the blowing bellows-like action which is produced by the movement of the flexible wall.

We declare that what'we claim is: 1. An interrupter for ignition apparatus comprising a movable contact, a stationary contact, a chamber having an opening therein enclosing said contacts, a flexible non-resilient covering on said opening connected with said movable contact and means to connect said chamber with the outer atmosphere.

2. An interrupter for ignition apparatus comnecting said chamber with the outer atmosphere of less volume than the volume displaced by said cover upon displacement of the rocking lever.

FRITZ ALLENDORFF. KARL SCHWEIZER. 

